In the area of distributing and feeding audio signals, many applications place great value on a high quality of the audio signals, and a good perceptibility of the latter at each point in a room. The quality and volume of audio contents can enhance the comfort of the listener depending on application, for example in stereo systems for private use or at concerts. However, the probability of passenger survival can also depend on a good perceptibility of audio signals at every point in a room in certain situations, for example during air travel when important announcements are being made from the cockpit.
Therefore, it is very important during air travel in particular that the pilot or crew announcements or safety demonstrations before takeoff be made readily audible to the passengers at every point in the aircraft cabin.
A plurality of individual loudspeakers allocated over the length of the cabin is today used for distributing audio contents within the aircraft cabin, for example announcements, onboard music, instructions and chimes (fasten seat belt signal, bell). The loudspeakers are here e.g. integrated in the passenger service unit (PSU) above the heads of the passengers, and operated via so-called passenger interface supply adapters (PISA). The propagation of sound waves emitted by the loudspeakers can by rough approximation be compared to spherical waves coming from point sound sources. For example, a loudspeaker system for an aircraft cabin is known from DE 10 2006 049 030 B.
The necessity of incorporating a plurality of loudspeakers can result in a major installation, wiring and maintenance outlay. Further, the high number of loudspeakers can entail a high power consumption.
Therefore, one object of the present invention may be regarded as providing a device that makes it possible to achieve an improvement of audio function or of the audio signals to be emitted within the room given a preferably constant or lower number of loudspeakers.